Method of desizing



PatentedJan'. 2, 1940' r Stanley 1. Garnett, Providence, R.

American. Gyanamid Company,

1., assignor to New York,

N.,Y., a corporation of Maine N Drawing. Application July 16, 1938,

* Serial No. 219,598

4 Claims. '(01. I 8--138) This invention relates to an improved process of desizing textiles.

In the past, textiles have weaving by removing the size, usually a carbohydrate, by using an enzyme. This process is open v In the first place,

the enzymes are expensive. Secondly, the process requires a relatively high temperature and is slow.

to a'number of difficulties.

It has been proposed to obviate some of the disad vantages in the use of enzymes by employing a used very cautiously or with specially rapid alkali neutralization. I

According to the present invention, all of, the economies of strongmineral acids. are obtained without any. of the disadvantagesv and in ad'dition, an improved product is obtained by using sulfurous acid as a desizing agent. Sulfurous acid is much cheaper than enzymes, it does not tender cotton goods in effective concentration, it involves no risk of injury to workmen as compared to sulfuric acid, produces whiter and softer goods and requires no penetrant. There is also a lower ash content in the goods than when enzymes are used. At the same time, a lowertemperature can be used with sulfurous acid which effects savings in steam. v 1 i It is a further advantage of the present invention that it can be used in the ordinary processes of treating goods without changing the equipment or procedure in any material way.

While the present inv desizing cotton piece goods, it may be also used for desizing other fabrics such as rayon, cellulose,

acetate and mixtures with other textiles, such as wool, linen, silk and the like.

The present invention can be practiced in-any suitable equipment as it requires only a vessel capable of resisting the mildly corrosive action of sulfurous acid and provided with means for heating the goods in sulfurous acid solution. Although the invention is in no sense limited to any particular equipment, it is anadvantage that the standard equipment may be used. Thus, for example, the desizing may be'effected in the quench box of any'standard singer by simply providing the box with a connection to a cylinder" or other source of sulfur dioxide gas and providing for the necessary temperature maintenance. While itis an advantage of the present invention that the de sizing can been dcsized after ention is especially for A be effected at from90 to 100 F. as opposed to 125 E, which is necessary with enzymes, the temperature 'is in no sense critical and hightemperatures may be used but they do not present any advantage which compensates for the additional cost of steam. ,Sul-

furous acid from 0.1% to 1.0% is recommended,

but higher or lower concentrations may be used. The invention will be described in conjunction with the following specific examples which illustrate typical embodiments of the invention. The

invention, however, is not limitedto the exact details therein set forth.

Example 1 Cotton goods are passed through a singer of standard design and then into the quench box which isfilled with a 0.5% solution of sulfurous acid obtained by bubbling sulfur dioxide gas vention that the goods can be permitted to stand thereinto, the solution being maintained at '100" 1' up to 4 days without injury to. the fabric. After thorough action of the sulfurous acid on the size, the goods" are then further processed in the normal manner which, with cotton goods, essentially involves kier boiling, followed by washing, souring, bleaching and the like. These further steps do not depart from standard practice and the .onlydifference is that the goods are whiter than would otherwise be the case.

Example 2 Rayon or cellulose acetate or mixtures with wool, linen, silk and the like are mixed in an aqueous solution of 0.5% sulfurous acid at 100 F. in a 200-gallon box. The goods maybe either in openor rope form. The goods are then permitted to lie for 2 hours," washed and boiled off with soap in the usual manner. No injury is noted and goods of exceptional whiteness are produced.

What I claim is: 1 w

'1. A method for desizing cellulose fabrics sized with a predominantly carbohydrate size which comprises subjecting the fabric to the action of an aqueous solution of sulfur dioxide.

2. A method of desizing cotton goods sized with a predominantly carbohydrate size which comdesizing is eflected at temner atures between 90 prises singeing the goods, quenching them in an and 100 F. l

- aqueous solution of sulfur dioxide, and permit'-' 4 A method according to claim 2 in which the ting the goods to stand for sufi'icient time to effect desizing is effected at temperatures between 90 I I 5 action of the sulfurous acid on the size. and 100 F.

3. A method according to claim 1 in which the STANLEY I. F 

